Telephonic transmitting instrument



(No Model.)

R. DUNGER.

TBLEPHONIG TRANSMITTING INSTRUMENT. No. 390,575. Patented Oct. 2, 188B.

N. PETERSY Pham Limugnphr, wnhi uuuuuu c.

Nrrnn STATES Aran rricn.

ROBERT VDUNGER, OF CHICAGO, ILLINOIS, ASSIGNOR OF FOUR-TENTHS TO VILLIAM L. COPELAND, OF SAME PLACE.

TELPHONIC TRANSNITTINGElNSTRUlVlENT.

SPECIFICATION forming part of Letters Patent No. 390,575, dated @cto-'eer 2, 1888.

Application tiled January 9, 1888. Serial No. 260.168. (No model.)

To all whom, it may concern:

Be it known that I, ROBERT DUNe-ER, M. D., of Chicago, Illinois, have invented certain new and useful Improvements in Telephonie '[ransmitting-Instruments, of which the following is a speciication.

The principal object of this invention is to provide a transmitting-instrument for longdistance communication. Other objects of the invention will be apparent from the subjoined description.

rlhe invention consists in applying the principle of leverage to increase the effect of the vibrations of the diaphragm; also, in a means .of adjustment of the microphonic contacts;

also, in certain other devices or combinations, as specified in the claims at the end hereof.

In the accompanying drawings I have shown so much of a telephonie transmitter containing` my invention as is necessary to an understanding ofthe same.

In the drawings, Figure 1 is a View of the back of the diaphragm, showing the lever and contacts. Fig. 2 is a vertical section through the middle of the diaphragm, but showing the lever and contacts in elevation. Fig. 3 is a top View of the parts in Fig. 1.

In the several figures, l is the diaphragm.

2 is a ring to which the diaphragm is secured.

3 is a clamping-ring, which fastens the diaphragm in place on ring 2.

4 are cups on ring 3, one at each side ol it.

5 is the basebar of the lever. It spans the diaphragm, and is provided with fulerumpoints 6, which rest in the cups 4t and constitute a very delicate fulcrum for the lever.

7 is the long arm of the lever. It is mounted on the base-bar 5, which supports it.

8 is a pin on the diaphragm, projecting back toward lever 7, with its end attached to the lever.

9 is a yoke at the upper end of lever 7.

10 is a bar or pencil of carbon or other suitable material supported in the yoke 9.

11 are two ears secured above the yoke 9 to the door or frame to which the diaphragmrings are attached.

12 is a rod mounted in bearings in the ears 11 and capable of turning therein. Its lnid- 50 dle portion is bent into a crank, as shown.

13 are rods or pencils of some suitable material, such as carbon. They are strung upon the cranked part of rod 12 so as to hang loosely thereon. Their lower ends rest against the bar I0. By turning the rod 12 the pencils 13 may be inclined more or less, and thus adjusted to bearwith greater or less force against the pencil 10.

14 is a milled head on one end of rod 12, by 6c which it may conveniently be turned in making the adjustment.

l5 is the usual flaring opening in front of the diaphragm.

16 represents the battery. 65

17 and 18 are the wires from the terminals of the battery, one connecting with one of the ears 11 and the other with the coil on the main line.

19 is the return-Wire connected with ring 3. 7o

20 are wires connecting ring 3 with bar 5 of the lever.

In operation the current passes Vfrom the battery through Wire 17, ear I1, rod 12, pencils 13, pencil 10, yoke 9, lever 7, bar 5, ring 8, Wire 19, coil 22, and Wire 18. The vibrations of the diaphragm, amplified by the lever, are transmitted by it to pencil 1i), and cause varia-tions of resistance between pencil 10 and pencils 13, thus causing variations of the cur- Se rent.

I ol' course do not limit myself to the precise `form and arrangement ofthe parts shown and described, as many modiiicat-ions may be made in them without departing from thespirit of my invention.

Vhat I claim is-- 1. The combination, substantially as set forth, of the diaphragm and the amplityinglever acted upon by the diaphragm and com- 9o posed of the base-bar 5, having fulcrum-points resting in fulcrum-cups at the side ofthe diaphragm, and the arm 7, carrying the contactpiece at its free end at a greater distance from the fulcrum than the point of connection with the diaphragm.

2. The combination, substantially as set` forth, of the diaphragm, the amplifying-lever having a yoke, 9, at its free end, the contactbar 10, supported by said yoke, and the hanging pencils 13, supported independently of the diaphragm and resting against the bar l0.

3. The combination, substantially as set forth, of the diaphragm, the lever to amplify its vibrations, the contact-pencil carried by the lever, and the hanging contact-pencils resting against the lever-pencil and adjustable as to their angle of inclination, so as to vary the pressure with which they bear against the leverpencil.

4. The combination, substantially as set forth, of the diaphragm, the contactpencil vibrated thereby, the hanging pencils resting 15 against said first-mentioned pencil, and the cranked rod upon which said hanging pencils are hung to adj ust their pressure against said iirst-n1entioned pencil.

ROBERT D UNGER.

Witnesses:

WM. S. BATES, C. C. LINTHIOUM. 

